1. Field of the Invention
The present invention relates to a dry, waterproof sunscreen composition, a method of applying the sunscreen composition (a delivery system for sunscreen products), a sunless tanning dihydroxyacetone based preparation, and a method for applying the dihydroxyacetone based preparation.
2. Description of the Related Art
The undesirable effects of overexposure to sunlight are well known. Such exposure can result in not only an uncomfortable sunburn but in prematurely aging skin, wrinkles, loss of skin elasticity, dermatosis and ultimately skin cancer. Sun screening is desirable in order to protect the skin from these, and other, adverse effects of solar radiation. The most dangerous solar radiation is the ultra violet (UV) radiation at wavelengths lower than 400 nm which includes both UVA and UVB radiation.
The sun protection factor (SPF) is a measure of the protection from the sun afforded by a sunscreen agent or composition containing a sunscreen agent. Compositions having higher SPF values provide more protection from solar radiation and are preferred. As used herein in reference to the compositions of the present invention, the term "Sun Protection Factor" or "SPF" is described in the Federal Register 58(90), entitled "Sunscreen Drug Products for Over-The-Counter Human Use" (1993 Sunscreen Monograph) (the monograph).
Conventional sunscreen compositions are typically in the form of a liquid, either a lotion or a cream. These compositions may be either oil or water based. The water-based emulsion serves mainly as an aid to disperse the active ingredients topically. The carrier water evaporates and leaves a thin film of active ingredients plus excipient deposited on the skin. The film remaining on the skin contains the product which protects the skin from ultraviolet radiation. The liquid applications of these sunscreen compositions are often messy or greasy to the touch. Also, the distribution of the active ingredients on the skin is uneven when using sunscreen compositions containing liquid. The user must wait for the liquid in the sunscreen compositions to dry.
Another limitation of the prior art is that many sunscreen compositions are not waterproof. When sunscreen compositions are waterproof, the user must wait for a specified time for the sunscreen composition to dry and for the waterproofing to become effective. The waterproofing in these compositions can be easily washed off prior to drying. The waterproofing in the current invention is effective instantly upon applying to the skin.
Current sunscreen compositions use emulsifiers to create an emulsion and allow the product to penetrate the skin. They also utilize preservatives which may sensitize the skin. These conventional sunscreen compositions may also irritate the skin. The current invention does not use an emulsion, and does not penetrate the skin, both of which reduces the risk of irritation or an allergic reaction to the skin and systemic immune suppression from repeated use.
Dihydroxyacetone is commonly used in compositions having dihydroxyacetone concentrations ranging from 3 to 8% w/w in the form of a gel, cream, lotion, or spray products. Typically, these products are applied by hand. Sprays are used by spraying the composition on the skin and rubbing the composition on the skin by hand to make the application more uniform.
Many complaints with these products relate to uneven color formation resulting in streaks or blotchiness. Products containing dihydroxyacetone can be applied to the skin to a maximum of about 2-2.5 mg/cm.sup.2. Applications exceeding this level cannot be "rubbed in" which leaves the feeling that an excessive amount has been applied. An application of about 2 mg/cm.sup.2 is preferable.
Currently available products require the user to estimate the amount of product dispensed and the size of the area that is to be covered. Repeated application at a specific application density is not possible. At application densities of 2 mg/cm.sup.2 or below streaking and blotchiness are not as severe but a uniform coating cannot be achieved by hand application. At lower levels (about 1 mg/cm.sup.2) the product cannot be uniformly spread over the skin because of the affinity of the skin for the small amount of dihydroxyacetone preparation present. The result is streaking and blotchiness. The resultant color variation is caused by the presence of some skin areas having virtually no coverage by the product.
U.S. Pat. No. 4,563,346 issued to Deckner on Jan. 7, 1986 discloses a delivery system for delivering topically active ingredients to the skin wherein the delivery system is formed of a water-in-volatile silicone emulsion which includes an interior water phase and an exterior silicone phase which contains the active ingredient to be topically applied. The preferred delivery system of Deckner includes a volatile silicone (decamethyl cyclopentasiloxane), a non-ionic emulsifier (dioleyl methyl glucaside), deionized water and alcohol. The sunscreen emulsion formulation of Deckner contains octyldimethyl p-aminobenzoic acid in addition to the ingredients of the delivery system. Once the sunscreen emulsion formulation of Deckner is applied to the skin, the water and volatile silicone evaporate, leaving a film of sunscreen agent on the skin which is resistant to water and perspiration, but is removable by washing with soap.
U.S. Pat. No. 5,047,232 issued to Kaplan on Sep. 10, 1991 shows a non-aqueous waterproof oil-based topical composition containing one or more water-in-oil emulsifiers and at least one cosmetic emollient. Also, in Kaplan there is disclosed a method for preparing a non-aqueous waterproof oil-based topical sunscreen composition. The sunscreen composition of Kaplan is an oil based liquid composition which is oily to the touch and has the other qualities of oil as well. U.S. Pat. No. 5,093,107 issued to Matravers on Mar. 3, 1992 describes a skin protective sunscreen composition, and method of making same, exhibiting enhanced water repellency and conditioning effects comprising ultraviolet blockers, aliphatic waxes and hydrophobic silicones disposed in a pharmacologically acceptable water-free carrier. The sunscreen composition of Matravers is water repellent, moisturizes the skin, and has a pleasant feel. The base contains a synthetic aliphatic wax which is a high molecular weight C.sub.16 -C.sub.36 saturated synthetic wax fatty acid admixed with one or more hydrophobic silicones into which one or more sunscreens is uniformly dispersed. The hydrophobic silicones include cyclomethicone, dimethiconol, dimethicone, phenyltrimethicone and the like. The sunscreen base can be utilized with a variety of conventional sun blockers.
U.S. Pat. No. 5,178,852 issued to Forestier et al. on Jan. 12, 1993 discloses cosmetic and pharmaceutical compositions containing derivatives of benzylidenecamphor which are wide-band sunscreens and antioxidants and are utilized in the treatment of cutaneous inflammations and allergies. Although the benzylidenecamphor compounds could be utilized in a variety of compositions, the compositions shown in Forestier et al. include water, oils and/or waxes.
U.S. Pat. No. 5,620,682 issued to Fogel on Apr. 15, 1997 discloses a variety of sunscreen compositions containing an emollient which is a neopentanoate ester. The neopentanoate ester of the Fogel Patent is an excellent skin moisturizer and serves the additional function of increasing the SPF factors of the sunscreen compositions. All of the sunscreen compositions prepared according to Fogel are liquids, and no solid/dry form of sunscreen composition is contemplated by Fogel.
U.S. Pat. No. 5,447,715 issued to Roberts on Sep. 5, 1995 describes a non-aqueous sunscreen composition containing an amount of a volatile silicone oil sufficient to maintain the SPF of the waterproof composition at a value greater than about 20, and a conventional non-aqueous sunscreen formulation or a conventional non-aqueous waterproof sunscreen formulation. The composition of Roberts could be a liquid, a gel or a semi-solid. This composition contains many ingredients including ozokerite wax, lauryl lactate, microcrystalline wax, carnauba wax, polybutene, otyl methoxycinnamate, octyl dimethyl PABA, benzophenone-3, benzoic acid, propyl paraben, octadecene-1/maleic anhydride, copolymer, talc, fragrance and Dow Corning 344 fluid. The Roberts patent does not disclose a solid sunscreen composition. Also, the more ingredients found in a topical composition, the greater the chance of an allergic response.
U.S. Pat. No. 5,445,815 issued to Siegfried on Aug. 29, 1995 shows a dry sunscreen composition which includes a highly cross-linked polymethacrylate copolymer powder combined with active sunscreen ingredients. The composition includes octyl methoxycinnamate, octyl salicylate, homosalate, menthyl anthranilate, actocrylene, benzophenone-3, propylparaben, BHT, PVP/eicosene copolymer, C.sub.12-15 alcohols benzoate, octyldodecyl neopentanoate, titanium dioxide, D&C yellow No. 5 aluminum lake and acrylates copolymer. The dry sunscreen of Siegfried utilizes a highly cross linked polymethacrylate copolymer powder as the application vehicle.
U.S. Pat. No. 5,676,934 issued to Siegfried on Oct. 14, 1997 discloses a dry sunscreen composition comprising effective amounts of octyl methoxycinnamate, octyl salicylate, homosalate, menthyl anthranilate, octocrylene, benzophenone-3, propylparaben, BHT, PVP/eicosene copolymer, octyldodecyl neopentanoate, C.sub.12-15 alcohol, benzoate, titanium dioxide and acrylates copolymer, and a method for making the dry sunscreen. A homogeneous dry sunscreen is disclosed by Siegfried. The sunscreen composition therein utilizes entrapment polymers, such as acrylates copolymers. The resultant dry sunscreen composition is a homogenous powder.
U.S. Pat. No. 5,747,010 issued to Geesin et al. on May 5, 1998 describes a method for protecting skin from the oxidative effects of ultraviolet A radiation including UVA-induced lipid peroxidation. The method disclosed therein comprises topically applying to the skin an effective amount of a photoprotective composition that contains a lipophilic antioxidant that does not have appreciable absorbance near wavelengths of 320-380 nm. The photoprotective compositions of Geesin can be in solid, liquid or aerosol form. The compositions can be formulated into a liposomal formulation, an emollient, a liquid, a cream, a gel, an ointment, a microemulsion, or a solution. The lipophilic antioxidant disclosed in Geesin includes butylated hydroxyanisole, butylated hydroxytoluene and ascorbyl-6-palmitate. Also, the sunscreen composition may include a sunblock agent and/or a sunscreen agent. The sunblock may include zinc oxide or titanium dioxide, and the sunscreen agent may include p-aminobenzoic acid and its derivatives, anthranilates, salicylates, cinnamates and their derivatives, naphtholsulfonates, benzophenones, dibenzoylmethane derivatives, and tannic acid and its derivatives. The protective means of Geesin is not, per se, a sunscreen composition but is a method of protecting the skin from the oxidative effects of ultraviolet radiation and is a fundamentally distinct invention from the present invention. Also, Geesin's means does not include waterproofing.
U.S. Pat. No. 5,700,452 issued to Deckner et al. on Dec. 23, 1997 describes emulsion compositions which are useful for imparting both an artificial tan to human skin and for providing protection to the skin from the harmful effects of UV radiation. The invention of Deckner et al. utilizes dihydroxyacetone in an oil-in-water emulsion sunscreen composition. The emulsion compositions do not address the need addressed by the current invention because, although both sunscreen and an artificial tan are addressed, there is no provision for the even application of the composition.
U.S. Pat. No. 5,705,145 issued to Miklean et al. on Jan. 6, 1998 discloses cosmetic compositions for providing an artificial tan to skin which comprises dihydroxyacetone and an azole in an acceptable carrier and a method for using the same. The invention of Miklean et al. does not provide a combination artificial tan and sunscreen. Also, a dry, even application is not provided for in Miklean et al., as an oil-in-water emulsion is utilized.
U.S. Pat. No. 5,741,480 issued to Ascione on Apr. 21, 1998 shows an artificial tanning cosmetic composition containing dihydroxyacetone, among other components. The cosmetic composition of Ascione is a water-in-silicone emulsion and does not include a sunscreen composition. It is unlike the present invention in that it does not contain a waterproof dry sunscreen composition as well as the dihydroxyacetone, nor does it provide for an even distribution of the composition claimed therein.
U.S. Pat. No. 5,229,104 issued to Sottery et al. on Jul. 20 1993 describes oil-in-water emulsion compositions useful for imparting an artificial tan to human skin. The emulsions therein contain paucilamellar lipid vesicles encapsulating an aqueous dihydroxyacetone solution. The invention of Sottery et al. may include sunscreen compositions. The oil-in-water emulsion composition does not contain waterproofing components and does not eliminate the potential for uneven distribution of the suncare composition.
U.S. Pat. No. 5,232,688 issued to Ziegler et al. on Aug. 3, 1993 discloses a composition and method for self-tanning of the skin which may include dihydroxyacetone and a variety of potential carriers. The invention of Ziegler et al. does not, however, include a sunscreening component. The Ziegler composition therefore does not meet all of the potential uses of the present invention in that it does not provide for even distribution of sunscreen and artificial tanning compositions on the skin.
U.S. Pat. No. 5,318,774 issued to Alban et al. on Jun. 7, 1994 describes stabilized compositions, preferably in the form of oil-in-water emulsions, for imparting an artificial tan to human skin. The water phase of these compositions contains dihydroxyacetone, as well as other compounds, and the oil phase contains fatty acids or derivatives thereto. These compositions may, alternatively, include one or more sunscreen agents. The invention of Alban et al. does not address the need for dry, waterproof suncare products. It also does not address the need for even distribution of the suncare compositions.
U.S. Pat. No. 5,514,367 issued to Lentini et al. on May 7, 1996 shows cosmetic compositions for artificially tanning the skin utilizing skin tanning agents and cyclodextrins. Dihydroxyacetone is an acceptable skin tanning agent to be utilized in the invention of Lentini et al. The cosmetic compositions therein are applied by hand or in a manner otherwise analogous to a method for applying cosmetics. The invention of Lentini et al. does not address the potential for uneven application of suncare products nor does it address the aspects of waterproofing and sunscreening.
U.S. Pat. No. 5,603,923 issued to Robinson et al. describes artificial tanning compositions which provide improved color development, and good chemical and physical stability. These artificial tanning compositions include dihydroxyacetone. The compositions of Robinson et al. tend to utilize oil-in-water emulsions or other emulsifiers and do not have the capacity for even application of the present invention.
U.S. Pat. No. 5,656,262 issued to Kurz et al. discloses skin-coloring powder mixtures which may contain dihydroxyacetone. Sunscreen agents may also be utilized in conjunction with the skin-coloring powder mixtures. The powder mixtures of Kurz et al. are designed to be utilized in cosmetic or pharmaceutical preparations which vary from gels to solid sticks but they are not designed to be evenly applied in the same manner as the present invention.
There is a strongly felt need for a dry sunscreen composition which eliminates the difficulties of the prior art. The term "dry" herein refers to non-emulsion, non-aqueous and oil-free; the term does not refer to a solid nor does it preclude a low viscosity liquid. A dry sunscreen composition, which is non-emulsion, non-aqueous, and that does not include oils, is desirable because such a composition would be less messy and would tend to distribute the active ingredient more evenly. Also, a waterproof sunscreen composition having a high SPF value is very desirable. It is especially advantageous to have a waterproof sunscreen composition that is applied dry so that no time must elapse prior to the sunscreen composition becoming waterproof.
In addition, there is a strong felt need for an ever application of dihydroxyacetone. A self-leveling application of dihydroxyacetone is ideal. It is desirable to have a dihydroxyacetone application which can be applied from a cloth or other application matrix and not require sprays, lotions or creams.
None of the above inventions and patents, taken either singularly or in combination, is seen to describe the instant invention as claimed. Thus, a delivery system for suncare products solving the aforementioned problems is desired.